ENSO-Rainfall Teleconnection over the Maritime Continent Enhances and Shifts Eastward under Warming

The Maritime Continent (MC), located in the heart of the Indo-Pacific warm pool, plays an important role in the global climate. However, the future MC climate is largely unknown, in particular the ENSO-rainfall teleconnection. ENSO induces a zonal dipole pattern of rainfall variability across the Indo-Pacific Ocean, that is, positive variability in the tropical Pacific and negative variability toward the MC. Here, new CMIP6 models robustly project that, for both land and sea rainfall, the negative ENSO teleconnection over the MC (drier during El Nino and wetter during La Nina) could intensify significantly under the Shared Socioeconomic Pathway 5-8.5 (SSP585) warming scenario. A strengthened teleconnection may cause enhanced droughts and flooding, leading to agricultural impacts and altering rainfall predictability over the region. Models also project that both the Indo-Pacific rainfall center and the zero crossing of dipole-like rainfall variability shift eastward; these adjustments are more notable during boreal summer than during winter. All these projections are robustly supported by the model agreement and scale up with the warming trend.

Automated summary

The Maritime Continent (MC) has a significant impact on global climate, but its future climate, especially the ENSO-rainfall teleconnection, remains largely unknown. New CMIP6 models show that the negative ENSO teleconnection over the MC could significantly intensify under the SSP585 warming scenario, leading to enhanced droughts and flooding, agricultural impacts, and altered rainfall predictability. These projections are supported by model agreement and scale up with the warming trend, with noticeable adjustments during boreal summer.